The present invention relates to a parts selection apparatus and parts selection system for selecting individual parts to assemble a product or semi-finished product using a computer.
Conventionally, a system that searches a database in which a plurality of parts are registered in advance and selects parts that satisfy desired conditions is disclosed in, e.g., Japanese Laid-Open Patent No. 7-254002.
In general, in a design procedure using such system, actual parts to be used in the manufacture corresponding to the individual components in design drawing data generated by an external CAD system are selected on the basis of desired conditions. Information associated with the selected specific part is reflected in (added to) the design drawing data, and information required for placing an order for the selected part is extracted. Then, generation of slips and drawings, and the like are done. For example, a CAD system for designing electronic circuits as a typical CAD system will be explained below with reference to FIGS. 1 and 2.
FIG. 1 is an explanatory view of the arrangement of circuit diagram data according to a prior art and shows an example wherein data of a circuit in a given unit in the manufacture such as a single printed circuit board or the like is divisionally generated as a plurality of circuit diagram data 51. In FIG. 1, reference numerals 52 and 53 denote graphic symbols indicating circuit elements, i.e., a resistor and capacitor, respectively. The respective symbols are connected via lines, as shown in FIG. 1. R1, C1, and the like are reference symbols assigned by the designer when he or she designed the circuit diagram to identify the individual circuit elements. A required rated value is defined beside each reference symbol. In the circuit diagram data in this state, a plurality of gate circuit elements, integrated circuit elements, or the like, which are a single part in an actual product, are often separately defined by a plurality of circuit diagram data 51 for the sake of convenience for the designer in design.
FIG. 2 is a flow chart for explaining the process flow in the manufacture of a printed circuit board according to the prior art, and steps S1 to S12 in FIG. 2 will be described in turn below.
Step S1: A circuit diagram is created by a CAD system.
Step S2: It is checked (design rule check: DRC) if the circuit diagram is correctly designed. More specifically, it is checked if items (rated values, and the like) required for selecting specific parts in a process later are input for the individual components (graphic symbols of circuit elements, the like) defined in circuit diagram data, and electrical wiring is correctly done, and so on.
Step S3: Graphic symbols that become a single part of separately defined circuit diagram elements are packaged and a single reference symbol is assigned.
Step S4: Predetermined items are extracted from the circuit diagram data 51 to search a plurality of pieces of part information pre-stored in a database, thus selecting parts to be used. More specifically, the rated values, supply numbers, or the maker's names and maker model names of the parts to be used are selected. Note that the supply number is an identification number which is defined for each part in the manufacturer which is to manufacture that printed circuit board, and is used upon ordering parts to the respective part manufacturers. Hence, in the mass-production of that printed circuit board, supply numbers are selected.
Step S5: Information associated with each selected part is added to the circuit diagram data 51 (to be referred to as back annotation: BA hereinafter).
Step S6: Actual shapes of a plurality of parts re-stored in the database are searched out on the basis of the information associated with the selected parts, and design data of a printed circuit board (PCB) is created.
Step S7: Layout of the printed circuit board in the actually assembled state of the individual parts is designed.
Step S8: Reference symbols are changed on the printed circuit board in the actually assembled state of the individual parts, so that the individual parts are easy to find. Also, the changed information is reflected in the circuit diagram data 51 to attain matching between the PCB manufacturing data and the circuit diagram data.
Step S9: Slips used in a supply department and manufacturing department are generated.
Step S10: Circuit diagrams and slips are plotted to distribute them in the form of paper sheets.
Step S11: After checking and approval, the plotted drawings and slips are delivered to the subsequent processes (supply department and manufacturing department).
In the above-mentioned prior art, information of each component defined in the design drawing data is extracted, a specific part is selected, and information associated with that specific part must be written again in the design drawing data. Conventionally, since this processing is provided with a specific CAD system, the parts selection system depends on the structure of design drawing data created by that CAD system and consequently corresponds to the specific CAD system. Hence, in an environment in which a plurality of types of CAD systems are used, since different data types (binary, text, and the like), formats, variable names, and the like are used in units of systems, a plurality of types of parts selection systems are required in correspondence with these CAD systems. As a result, it is hard to learn operations of such systems, and parts selection data with different formats are present, thus making data management and part supply difficult. Upon outputting slips and drawings in the manufacturing department or supply department as the subsequent process, since many factors depend on the specific CAD systems used in the design process, a slip in a required format cannot be obtained.